The present invention relates to a formulation having a mineral-ion exchange resin complex that is useful as a dietary supplement.
A variety of commercial products are available which have been described as being useful as dietary supplements and/or for treatment of certain mineral and vitamin deficiencies. Such products have been formulated for either pediatric delivery (infants and children) or for adults (including the geriatric population). Depending upon the target population, such products are available as liquid suspensions, powders, tablets and/or other solid forms. Certain of these products, including, notably, those containing iron supplements in liquid form, have been reported to have undesirable side effects including, e.g., gastric irritation and stomach upset, staining of teeth, and a less than desirable taste. See, e.g., side effects listed on product label for Fer-In-Sol® iron supplement [Mead Johnson], “Pharmacy and Therapeutics Committee Medication Review, May 21, 2004, citing Drug Facts and Comparisons, updated November 2003.
Use of ion-exchange resins to form a drug-ion exchange resin complex is well known and is described, for example, in U.S. Pat. No. 2,990,332. In the '332 patent, the use of an ion-exchange resin to form a complex with ionic drugs and thereby delay the drug release from such complexes is described. Such delay in drug release was deemed to be of relatively short duration. Since then there have been additional publications and patents (e.g., U.S. Pat. Nos. 3,138,525; 3,499,960; 3,594,470; Belgian patent 729,827; German patent 2,246,037) that describe use of such ion-exchange resin complexes with water-permeable diffusion barrier coatings of the drug-ion exchange resin complex coated to alter the release of drugs from the drug-ion exchange resin complex. Ion-exchange resin complexes have also been described by their manufacturers and in the literature as being useful for taste masking of unpleasant tasting drugs [Rohm and Haas].
Additionally, analysis of the iron state in some iron-containing vitamins and dietary supplements has revealed higher amounts of ferric impurities than is desirable or permitted under FDA standards. See, Oshtrack et al, Analytica Chimica Acta, 506 (2004) 155-160. This article reports that due to concerns regarding toxicity of ferric iron, the FDA has indicated the ferrous fumarate dietary supplements should not contain more than 2% ferric iron. The article also reports that several marketed formulations tested off the shelf have been found to have higher ferric contents that permitted by the FDA due to oxidation.
Alternatives to the formulations currently on the market for dietary supplements are desirable.